Two-factor authentication adds an additional layer of security by adding a second step to the login process. It takes something you know (ie. your password) and adds a second factor, typically something you have (such as your phone). Since both are required to log in, the threat of a leaked password is lessened.

One of the most common and simplest forms of Two-Factor Authentication is Time Based Tokens. With Time Based Tokens, in addition to your regular username & password, you also have to enter a 6 digit code that re-generates every 30 seconds. Only your token device (typically a mobile smartphone app) will know your secret key and be able to generate valid one time passwords for your account.

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